2014-72-4Relevant articles and documents
Ligand-Enabled β-C(sp3)-H Olefination of Free Carboxylic Acids
Zhuang, Zhe,Yu, Chang-Bin,Chen, Gang,Wu, Qing-Feng,Hsiao, Yi,Joe, Candice L.,Qiao, Jennifer X.,Poss, Michael A.,Yu, Jin-Quan
, p. 10363 - 10367 (2018)
An acetyl-protected aminoethyl phenyl thioether has been developed to promote C(sp3)-H activation. Significant ligand enhancement is demonstrated by the realization of the first Pd(II)-catalyzed olefination of C(sp3)-H bonds of free carboxylic acids without using an auxiliary. Subsequent lactonization of the olefinated product via 1,4 addition provided exclusively monoselectivity in the presence of multiple β-C-H bonds. The product γ-lactone can be readily opened to give either the highly valuable β-olefinated or γ-hydroxylated aliphatic acids. Considering the challenges in developing Heck couplings using alkyl halides, this reaction offers a useful alternative.
Synthesis of Cyclic Anhydrides via Ligand-Enabled C–H Carbonylation of Simple Aliphatic Acids
Herron, Alastair N.,Yu, Jin-Quan,Zhuang, Zhe
supporting information, p. 16382 - 16387 (2021/06/23)
The development of C(sp3)–H functionalizations of free carboxylic acids has provided a wide range of versatile C?C and C?Y (Y=heteroatom) bond-forming reactions. Additionally, C–H functionalizations have lent themselves to the one-step preparation of a number of valuable synthetic motifs that are often difficult to prepare through conventional methods. Herein, we report a β- or γ-C(sp3)–H carbonylation of free carboxylic acids using Mo(CO)6 as a convenient solid CO source and enabled by a bidentate ligand, leading to convenient syntheses of cyclic anhydrides. Among these, the succinic anhydride products are versatile stepping stones for the mono-selective introduction of various functional groups at the β position of the parent acids by decarboxylative functionalizations, thus providing a divergent strategy to synthesize a myriad of carboxylic acids inaccessible by previous β-C–H activation reactions. The enantioselective carbonylation of free cyclopropanecarboxylic acids has also been achieved using a chiral bidentate thioether ligand.
PROCESS FOR THE PREPARATION OF N-[(3-AMINOOXETAN-3-YL)METHYL]-2-(1,1-DIOXO-3,5-DIHYDRO-1,4-BENZOTHIAZEPIN-4-YL)-6-METHYL-QUINAZOLIN-4-AMINE
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Paragraph 0069; 0070, (2016/11/24)
The present invention relates to a novel process for the preparation of a compound of the formula (I): and pharmaceutically acceptable acid addition salts thereof, which is useful for prophylaxis and treatment of respiratory syncytial virus (RSV) infection in mammal or human being.